The objectives of this proposal are to perform chemical sequencing analysis of the glycolipid and glycoproteins of normal and abnormal (acute and chronic leukemia) human white blood cells (lymphocytic and myeloid), and to determine: can these compounds be used as tissue-specific and leukemia-specific markers, are they clinically important alloantigens, and what ar their biologic roles? For complete chemical structural anlaysis the following methods will be used: gas-liquid chromatography (GC), direct probe mass spectrometry (MS), combined GC-MS, and glycosidase treatment. High pressure liquid chromatography will be used to analyze changes in distribution of glycolipid and glycoprotein oligosaccharides in different leukocyte disorders. The role of these molecules in leukocyte transfusion will be determined by testing the ability of these molecules to remove activity from antisera to leukocytes obtained from patients with immune-mediated neutropenias or a history of repeated leukocyte transfusions. Results from the chemical analyses will allow us to determine the variations in glycosphingolipid & glycoprotein antigens among white blood cells of different origins (lymphoid and myeloid) and to evaluate the usefulness of these compounds in diagnostically differentiating leukemias. It will also be possible to correlate these chemically defined antigens with known serologically defined "leukemia associated antigens". Results of the immunologic studies will also permit us to determine what role glycosphingolipids and glycoproteins play in leukocyte transfusion and immune leukopenias.